731791440 has 120 divisors (see below), whose sum is σ = 2467027368. Its totient is φ = 194396160.

The previous prime is 731791393. The next prime is 731791453. The reversal of 731791440 is 44197137.

It can be written as a sum of positive squares in 4 ways, for example, as 2143296 + 729648144 = 1464^2 + 27012^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 731791395 and 731791404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 200512 + ... + 204128.

Almost surely, 2^731791440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 731791440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1233513684).

731791440 is an abundant number, since it is smaller than the sum of its proper divisors (1735235928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

731791440 is a wasteful number, since it uses less digits than its factorization.

731791440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3917 (or 3908 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 731791440 is about 27051.6439426516. The cubic root of 731791440 is about 901.1472776238.

The spelling of 731791440 in words is "seven hundred thirty-one million, seven hundred ninety-one thousand, four hundred forty".